Wall form



March 16., 1943. w, R, B AGQ l wm. Form Filed June 1'7.A 1940 2 sheets-'snaai 1 lNvENToR WILL/HM E- BHET BY Sms Mok@ 'ATTORNEYS 2 Sheets-Sheet 2 W. R. BAGOT WALL Form Filed June 17, 1940 Mmh 16, '1943.`

INVENTOR W/LL/HM E. BAGOT' ATTORNEYS BYNMM 1 www :i -l w Patented Mar. 16, 1943 UNITED lSTATES PATENT OFFICE p WALL FORM William It. Baget, Alameda, Calif. v vApplication June 17, 1940, Serial No. 340,941

12 Claims.

This invention relatest'o forms and a method for constructing hollow concrete walls. It has for its objects an improved wall form construction enabling cheaper and faster construction of hollow or cellular concrete wallsthan heretofore. Another object is an improved method of forming a hollow concrete wall with a minimum of forms and expense. Still another object is the construction of a hollow concrete wall by utilizing an inside and an outside metal form arranged to allow the'wet concrete to flow between the inner andouter forms to form vertically extending hollow concrete walls with columns of the same thickness as the wall spaced at regular intervals. A still further-'object is an improved wall form construction for making hollow or cellular concrete walls of stronger construction than heretofore -'and providing intercommunicating passageways in such wallsfor connecting the cells therein. Another object is an improved wall form construction which may be used over and over again with a minimum of effort and expense. Yet another object is an improved inner form construction which is adjustable for forming cells of different sizes.

Yet another object is an improvedconcrete wall with means imbedded therein duringpouring of the concrete releasably securing surface accessories to one or both sides of the wall. Still another object is the provision for a pouring chute adapted to be used with hollow concrete wall forms. Other objects and advantages will appear in the speciiication and drawings annexed hereto. s

In the drawings, Fig. 1 is a horizontal plan view of a portion of my invention with the forms properly positioned and anchored. n

Fig. 2 is a. partial side view, partially in section, of the inner forms alongthe line 2-2 of Fig. 1.

Fig. 3 is a sectional end View of the `inner forms, taken along the line 3-3 of Fig. 2.

Fig. 4 is a side view, partially in section, of the tie bar with the spacer andone outside wall (in section) in position relative to said tie bar.

Fig. 5 is an end view of .the tie bar shown in Fig/l with the spacer (partially shown) inposition..

Fig. 6 is a side viewofthe Spacer showing the `walls of the inner forms and.-the tie-bar (in-section)V in position.

Fig. 7 is a fragmentary plan view of the abutting ends ofone ofthe outside forms.

Fig. 8 is a side view of a -flue box, comprising of the wall.

bolts are run both to attach one form of spacer with the inner forms being shown in section.

Fig. 9 is a view taken at right angles to Fig. 8, showing portions of the tie bar in position with the box bolt in cross-section. Fig. 10 is a diagrammatic plan view, the forms in position on the foundation, with the inner and outer forms being indicated by single lines.

Fig. 11 is a fragmentary elevational View of the forms in position illustrating how the forms may be supported on the foundation.

Fig. 12 is a sectional view of the forms in position just before pouring, taken along the line I2--I2 of Fig. 1l.

Fig. 13 is a top View of a portion of the forms showing how they may be utilized to form a window or other opening in the wall.

' Fig. 14 is a vertical sectional View of the pouring chute in position.

Fig. l5 isA an end View of the Wall partially in section, showing surface accessories secured to the wall utilizing the tie bars.

- In detail, my invention consists of two sets of forms, an inner form and an outer form arranged one Within the other so that when concrete is poured between the two sets of forms, there is a hollow cell left in the central portion The outer forms are composed of flat steel plates held together by tie bars. One end of each plate isprovided with a Short overlapping plate so that when adjoining plates are shoved together, the overlapping plate prevents a loss of concrete. The outer forms are also provided with holes properly spaced through which the lower side o-f the plates to the completed section of the wall, and to hold the upper end of the plates together by means of the tie bars, when the concrete is poured.

The inner forms comprise a series of horizontally spaced vertically extending tubular members with each tubular member divided vertically into two sections adapted to be held together. Each section has, when viewed from above, whenithe inner forms are in position, a U-shape. The sections comprising the tubular member may be of exactly the same size or one section may be formed into a slightly broader U-shape. In either case, the legs of the U-shape of one section are designed to t telescopically within the legs of the other section. Although the sections are easier to position if one is slightlyl larger, substantial advantage is to be gained by the use of sections of the same size. This is due to the fact that the legs of one section will have to be sprung to permit insertion of the legs of the other section, which springing forms a tight seal between the two sections to keep the concrete from running into the central cell. The pair when positioned, form a substantially rectangular cross-sectional area. They are fitted with ears provided with holes so that the sections may be anchored together and their walls held apart against the pressure of the concrete.

Tie bars are designed to be used to hold the outer walls together and are positioned in the concrete columns between the adjacent tubular members. These outside tie bars are formed with parallel plates, with an opening between, through which is passed a spacer at right angles to the tie bar and welded thereto. The whole unit is in the form of a cross, and in connection with the threaded bolts used, it may be inserted in the holes of the forms so that the forms may be rigidly held. This tie bar spacer arrangement is ordinarily near the top of the forms, so that when the Concrete sets, the bolts are loosened, the forms removed and moved up and again attached by their lower holes to the tie bars which have remained imbedded in the concrete.

If connecting passageways are desired between the hollow cells, tubular spacers with open ends can be used, into and through which the tie bar may be positioned.

The method of using my invention involves preparing the foundation with a hollow center into which the inner forms may be set with means for bolting both the inside and outside forms to the wall provided in the foundation. The forms are bolted to this preformed foundation with perhaps 1A; to 1/3 of their height overlapping it and tie bars and spacers are positioned at the upper ends of the forms. The concrete is then poured and allowed to set. The forms are then unbolted from the foundation holding means and from the imbedded tie bars and spacers and pulled up to a point where the lower bolt holes in the plates are in alignment with the im- Ibedded tie bars where the forms are again bolted and the process repeated. It will be seen that the inner forms may be partially collapsed due to their U-shape, and pulled up inside the wall, and are never removed from within the hollow cell till the wall is completed. The outside forms are constructed in sections large enough to form a length of wall including several hollow cells although in a vertical direction they are the same height as the inner forms.

The outer forms are formed of rectangular steel plates I in which are drilled holes 2 (Fig. 4), and whose horizontal length is sucient to extend along the wall a distance corresponding to the Width of several columns in the finished wall. Each plate is fitted with a line of holes 2 near its lower edge and another line of holes near its upper edge spaced horizontally to coincide with the center of the concrete columns to be formed in the wall.

Near one end of each plate I, and on the outside face is welded a long narrow steel protective :plate 3 so that it extends over the end of pla-te I as shown in Fig. 7. Thus, when the abutting ends of adjoining plates are brought together, protective plate 3 extends along and over the joint and prevents concrete from owing through the joint. The weld can be made in any convenient manner, but preferably at the edge 4 of the plate 3 facing plate I.

The inner forms are constructed of tubular members formed in pairs of vertically extending sections 5 and 5 which are .bent so as to form a U-shape when viewed from above. Preferably, the legs and base of the U-shape of either sections 5 or 5' are made from a single piece of sheet 'metal bent into the U-shape. The bends are not right angle bends, but as shown in Figs. 1 to l0, the corners are preferably bevelled, at approximately 60 to the extended line of the leg. This type of ben-ding obviously allows a stronger coluann to Ibe poured and spreads the strain ordinarily found at right angle bends over a larger area. Two holes 23 (Fig. 6), are drilled in each section of the inner forms, centered at the base of the U, one being substantially near the top of the section and the other substantially near the bottom for receiving bolt 22 to be described later. The sections are so formed that when their legs 6 and 6v are positioned to extend towards one another, the legs 6' of the sections 5 fit telescopically between the legs 6 of the sections 5. It is obvious that by varying the distance which legs E are slide into section 5, the size of the hollow cells in. the concrete can be changed to any desired dimensions, within certain limits.

The sections 5 are provided with horizontally inwardly extending ears 'I in each of which there are holes 8 for receiying locking pins 9. These ears are located substantially near the end of the vlegs 6 and extend inwardly. One or more ears 'l may be mounted on legs 6, two being indicated in the drawings in a verticalI line, one located near the lower end of the section 5, and the other near the upper end. Each leg 6' of the section 5 is tted with slot or slots I0 through which the ear or ears 'I in legs 6 may be inserted. There are two sets of these slots I0, each set in vertical alignment, but horizontally spaced from the other set so that either set may be used depending uponhow far the legs of sections 5 are slipped into sections 5. This, as explained above, allows the size of the hollow shafts in the wall to be varied. Of course, it is obvious that any desired number of sets of these slots may be added. However many sets of. slots I0 are provided in legs 6', legs 6 should be long enough to extend over and cover all the slots to prevent 4concrete from owing into rthe slots thereby making impossible the removal of the sections 5.

The ears 1 are arranged to be inserted in these slots I0 by forcing the legs 6 together and allowing them to spread. This locks the two sections together when the pins 9 are inserted. The pins 9 not only lock the sections from slipping relatively to one another, but assist in holding the inner forms apart when the concrete is poured around them. Said :pins are formed from steel rods lbent into a right angled U--bar with the ends of the legs .being tapered to facilitate inserting them in the holes 8 in ears l.

The ears I are formed from bar steel bent into right angles with the hole 8 drilled into the horizontally extending leg of the angle. The vertical leg is attached to legs 6 of sections 5 by any suitable manner, preferably welding.

Each of the sections -5 and 5 has, near the center of its sides, two additional ears, I I on section 5 and II on section 5'. These ears are the same as ears 1, one fastened on each leg and positioned to extend inwardly toward the other in the same vertical and horizontal planes. The ears are provided with holes I3 corresponding to holes 8, in the horizontal legs of the ears through which is positioned locking rods I2 and I2', steel rods triangularly shaped with their shori-l legs horizontal and extending from the ears on the legs of each section to the ears on the otherv legs. The `longer'-sides of the triangle extend' downwardly convergently.- through holes i3 so that by pulling the shortlhorizontal leg of the rod vtriangle,` the-legs-of the sections 5 and 5' will be pulled together to facilitate insertion and removal ofthe forms within the wall. The inner and outer forms are connected by lvarious'means depending upon the results desired. Ordinarily the outer forms will be con# nected together by a tie bar I4 (Figs. 4 and 5) Vdesigned to be bolted to outside form plates l through-bolt' holes 2,'by means of nuts l5. This tie" bar comprises two parallel strips-of metal I6 with their ilat surfaces facing one another.` At -each end of this pair of strips I6 is a small metal -witheah end threaded; but`the\threaded ends 'have a"smaller diameter than the central portion so that the stud bolt i5 may be screwed into hole I8 till thecentral portion of the bolt con- "tacts the block; and also so that the other threaded` end 'may t ihto one'of the holes 2in outside plates YIQ' The' stud -bolt- I9 is also provided at the one 'of the" threaded ends intended to be '--i`nserted in holes 2 with a square end 20, which is adapted to fit a wrench (not shown) for turn- 'Aing the stud bolt i9 out of the concrete when theoutside plates i have been removed.

` "Between the parallel strips I6 of the tie bar I4,

halfway between the blocks Il, and at right angles to the length of said tie bar is a U-shaped spacer 2| with the base' of the U welded to the upper of stapels and tnenegs of the. u welded to the lowerof strips" l5'. The length of the spacer 2| is the same as'the -distance between adjacent inner formswhich allows it to serve as a brace between the inner forms. The construction of fthe tie bar' I4 and'the 'spacer 2l makes it serve 'also -as abra'c'ebetween the outer-plates l since '-thetwofare welded together. A bolt 22 with one threaded endfisdesign'ed to be used` with spacer 2| by placing it through holes 23 in sections 5 or--5of the inner form so that it runs under and iswprotectedi from'the concrete during pouring by, spacer-21, and then through the aligned hole -in the section, 5 or 5 of the adjacent inner form.

A nut 24 is screwed onto thethreaded end of the =`.bolt 22 'tolock the spacer 2| in place.

1 Theform of spacer and tie bar integrally connected i's the-form .which is ordinarily used. However, should it be desired to use the hollow cells "for heating or'` other purposes, connecting passageway-s can be provided extending through the columnfrom one cell to an' adjacent cell. Provisionfor suchpassageway is made by the use fofa hollow'me'tal-bo'x 25 (Figs. 8 and 9) which Eis' us'ed'in connection with the tie bar instead of 'the spacer 2 l; 'The box 25 is substantially square with open ends.;v The sides of the box are cut open at the top torece'ive the tie bar I4 which exft'ends completely through the box with the ends 'extending beyond it for attaching the ne bar to :theoutsidellform plates l. Thus, the box 25 is jsubstantiallylike a spacer 2l, except that when the forms are removeda passageway is opened between the central cells of the wall. The same jl bolt b 22 Vand' nut 2li may be `used `with box 25 as is ns'edwvithspacer thand the box may be integral with ne taria if desired;

My invention mayalso be easily transformed so that `spaces may beleft'for windows, doors, etc., in the wall at proper intervals. When the location of such an opening is determined,`one or more of the pairs of inner form sections 5`and 5' are left out of the wall andilat metal plates 26 (Fig. 13) Aare attached to the unattached end of the spacers 2 l by means of the bolts 22 and nuts 24. This plate 26 is designed to fit within the outer'platesl in a vertical plane and at right angles to the length of the wall. These plates 26 prevent the concrete poured between the inner and outer forms from running into the space between the plates 25, so that when the forms are removed an opening is left. When the wall has been raised' to a suicient length along'the sides of the door or window opening, a suitable bottom can be inserted in the forms and the sections 5 and5 replaced.

In operation, the foundation is prepared with suitable holding means and suitable central shafts to receive the plates of the outer and inner forms. The formsare placed using the ordinary tie bars I4 and spacers 2l unless the connecting conduits are needed. When the forms are all bolted and locked into place, the concrete is poured into the spacesbetween the inner and outer forms. When the concrete has been allowed to set, the nuts 24 are loosened on the inside of sections 5 and 5 andthe bolts 22 are driven out. The pins 9 are removed'and rod l2 is then pulled up to collapse section 5 so that it may be pulled up to a point where the lower hole 23 is in alignment with the hole left in the column when bolt 22 is removed from the upper hole 23. The same procedure is'used on section 5. At this point,

I pins S'are reinserted, bolts 22 are again inserted in the lower .holes 23 and the section is bolted to the' wall and spacer tie bar 2l land lf3 are placed between the upper Yholesf23 in the sections of the inner forms.

Withthis'operation completed, the plates I are removed by removing'the nuts i5 and the plates' I are hoisted to the new position where the loWer holes v2 in the plate are in alignment withthe endof the stud bolt I9 originally in alignment with 'the lower holes 2 and which now protrudes from the concrete. The plates l are now bolted to these stud bolts by means of nuts i5 and to the tie bars i4 in'alignment with the upper holes 2. Since both the inner and outer forms are now in place, the concrete is again poured and the removal process repeated until the desired height of the wall is obtained.

With my forms I have also designed a pouring chute 21, (Fig. 14)- for concrete, to prevent concrete from being wasted either by pouring it outside the forms or inside the hollow cells. The chute is composed of plates 28 and 29 secured together by bar 30. The plates 28 extend a short distance down between the inner and outer forms adjacent 'plates i and divergeoutwardly from thewall above it as shown in Fig. 14 so that in v.cross-section they are funnel-shaped. 'A cap over the shaft is formed by the plates 29 'which extend downward into the forms as do plates 28, but`adjacent to sections 5 and 5. Plates 29 'extend out of the forms and toward one another and the center of the form where they meet to form a pointed cap over the hollow cell. All the'plates are bolted together by one or' more horizontally extending bars 3Q. YThe chute 21 'may b e as long as is desired or as is convenient to use.

'7 `As well'as being a-new and -easy method-of erecting hollow concrete walls, my invention also provides means for attaching any of various useful surface accessories to the completed wall. Ordinarily, stud bolt I9 is screwed out of block II after the forms are removed by means of a wrench operating on the square end 20. The resulting hole in the wall may be filled up `as is shown at 3| in Fig. 15. But if the hole is left open, since the block II provides a threaded holding means shelving 32, re escapes or scaffolding 33, moulding or base boards 34, or any other of various articles can be attached to the wall by means of bolts screwed into the imbedded tie bars I4.

Here again, the construction of the tie bar I4 and spacer 2| should be noted. Since the two parts are welded together at right angles and imbedded in the nished columns, it is obvious that any force exerted by pulling or turning effected by the surface accessories will be spread over a large area. It would be impossible to pull the tie bar out of the column without tearing down the column by virtue of the fact that the connected spacer extends across the whole column.

It is obvious that my invention, as described herein, is to be used with the ordinary methods of reinforcing. The tie bars, spacers and boxes may be so used as not to interfere with the reinforcing steel and in some cases the two may be locked together to form an even stronger wall. The reinforcing steel is not shown in the drawings sc that they may be as simple as possible, but it is obvious that it may and should be used with mv invention.

Having described my invention, I claim:

1. A wall form including a pair of vertically disposed walls of sheet material in spaced opposed relation and a pair of vertically disposed tubular members between said walls spaced therefrom and spaced from each other to provide for concrete between said members and between said walls and said members, vertically spaced means releasably securing said walls and members so spaced from each other, each of said members being vertically separated into a pair of sections each of substantially U-shape in horizontal cross-section, the said sections of each member having their adjacent marginal portions in overlapping relation, means releasably securing each pair of sections together and means carried by each member at said overlapping portions of the sections thereof and spaced from the opposed ends of said sections within each of said members releasably supporting the opposed sides of each section against movement inwardly toward each other, the respective sections of each pair being formed from a single sheet of metal.

2. A wall form including a pair of vertically disposed walls of sheet metal in opposed relation and a pair of vertically disposed tubular members between said walls, a generally cross-shaped unitary device disposed between said members spacing said members apart and releasably securing said walls together in positions spaced from each other and spaced from said members whereby, upon pouring concrete between said walls and between said members a hollow wall and solid column will be formed, said one of the oppositely outwardly extending pair of arms of said cross-shaped device comprising a pair of parallel elongated bars disposed between said walls perpendicular thereto whereby said concrete will ow between said bars, a pair of coaxially aligned nuts respectively positioned at each opposite end of said pair of bars rigidly secured thereto, a pair of oppositely outwardly extending` bolts threadedly secured in said nuts, at their' adjacent ends openings formed in said walls through which said bolts extend to the outside of said walls, and means on said bolts outwardly of said walls securing said walls against separation the space between said bars being adapted .to` receive concrete for solidly anchoring said bars and the nuts carried thereby in the column. of concrete adapt.- ed to be formed between said tubular members whereby upon removal of said bolts from said nuts the latter Will provide means firmly anchored in such column for re-engagement with bolts for bolting desirable elements to either side of the concrete wall to be formed, and means releasably secured on the other pair of said arms of said oros-shaped device adaptedv to rmly se.- cure said tubular member to said other arms respectively.

3. A wall form including a pair ofi vertically disposed walls of sheet metal in opposed relation and a pair of vertically disposed tubular members in side by side relation positioned between said walls, vertically spaced generally cross-shaped devices disposed between said members respectively having oie pair of horizontal co'axial arms spacing said members apart and another pair of horizontal co-axial arms releasably securing said walls together in positions spaced from each other and spaced from said members, and means releasably securing said members in positions so spaced apart.

4. A wall form including a pair of vertically disposed walls of sheet metal in opposed relation and a pair of vertically disposed tubular members disposed between said walls, meais positioned between said members spacing said walls from said members and spacing said members from each other, said means including a tubular open ended device extending between said members with the edges at said open ends abutting said members, said device being of substantial diameter for providing a relatively large opening between said members whereby upon pouring concrete between said members to form a column and removal of said members after setting of such concrete, a relatively large open ended passageway will be formed in said column.

5. In a construction as defined ln claim 4, means extending through said device and through the adjacent walls of said pair of tubular members releasably securing said members against opposite ends of said device.

6. A wall form including a pair of vertically disposed rectangular walls of sheet metal in opposed relation and a plurality of vertically disposed pairs of spaced tubular members positioned between said walls, horizontally aligned openings in said pair of walls arranged in horizontally extending rows adjacent the upper and lower edges of said walls, adjacent sides of the tubular members of each pair provided with openings adjacent upper and lower ends of said members at substantially the levels of the rows of openings that are adjacent the upper and lower edges of said walls, means positioned within the space between adjacent members of each pair releasably secured in the said openings in said members and walls, respectively, securing said walls in positions spaced from said members and securing the members of said pairs in said spaced relation to each other.

"1. A core for forming the hollow interior of a concrete wall comprising a vertically extending tubular member open at its upper and lower ends,

said member being vertically divided to form a pair of generally U-shaped sections having their open sides facing toward each other, means within said tubular member releasably securing said sections together, and section collapsing means movably supported on each section and wholly disposed between opposed sides of each section for drawing the adjacent edges of the pair of sections toward each other to collapse said sections, said sheet sections being a resilient sheet material whereby the sections will ex about vertical axes at their closed ends upon said adjacent edges being drawn toward each other, said collapsing means comprising generally U-shaped bars with the legs thereof extending convergently from the closed end or the U, and lugs projecting inwardly from opposed sides of each section, each provided with a vertical opening through which one of the legs of said bar slidably extends.

8. A core for forming the hollow interior of a concrete wall comprising a vertically extending tubular resilient sheet metal member open at its upper and lower ends, said member being vertically divided to form a pair of generally U- shaped sections having their open sides facing toward each other, the adjacent marginal portions of the sections along said open sides being in overlapping relation, means directly at said marginal portions releasably securing said adjacent marginal portions together at opposite sides of said member and spacing the said marginal portions at one of said opposite sides from the said marginal portions oppo-site thereto.

9. A core for forming the hollow interior of a concrete wall comprising a vertically extending, tubular, resilient, sheet metal member open at its upper and lower ends, said member being vertically divided to form a pair of generally U- shaped sections having their open sides facing toward each other, the adjacent marginal portions of the sections along said open sides being in overlapping relation with the marginal portions of one section outside the marginal portions of the other section relative to the center of said member, means carried by the marginal portions of the section that are outwardly of the marginal portions of the other section projecting through the said latter marginal portions, releasable means releasably securing said last mentioned means together, other means wholly disposed Within said member and carried by said sections respectively for moving the marginal portions of each section toward each other upon release of said releasable means, whereby said sections may be released from the concrete adapted to be poured around said member.

10. A wall form including a pair of vertically disposed walls of sheet material in spaced opposed relation and a pair of vertically disposed, tubular members positioned between said walls and spaced therefrom and spaced from each other to provide for concrete between said members and between said walls and said members; each of said tubular members being a pair of separable sections of substantially U-shape in horizontal cross-section with their open sides in confronting relation and positioned with the closed end of a section of one member adjacent the closed end of a section of the other member, an element carried by said adjacent closed ends and extending therebetween securing said ends together in spaced relation, and a tie-bar carried by said element extending between said walls securing said walls together in positions respectively spaced outwardly of opposite sides of said tubular members.

11. A wall form including a plurality of adjacent pairs of vertically disposed, similar sized, rectangular plates respectively positioned in a pair of horizontal rows with the plates in one row disposed directly opposite to the plates in the other row; a pair of horizontal tie-bars respectively positioned adjacent the upper and lower edges of each plate but equally spaced from the edge adjacent thereto; each of said pairs 0 of tie-bars being positioned in a vertical plane bisecting each opposed pair of plates, and means removable from said tie-bars at the outer ends thereof engaging the opposite outer sides of each pair of opposed plates for removably securing such plates thereto, a plurality of adjacent pairs of spaced tubular core members in a horizontal row disposed between said rows of plates and spaced therefrom; the adjacent sides of each pair of adjacent tubular members terminating at opposite sides of each of said pairs of tie-bars: means carried by each of said tie-bars extending between said adjacent sides of said tubular members spacing the said adjacent sides apart; the opposed plates in each of said rows being formed with openings into which the opposite ends of each tie-bar is iitted for removal of said ends from said openings when the said means carried at the outer ends of said tie-bars are removed from the latter, whereby the opposed pairs of plates in said rows may be raised after the setting of co-ncrete to be poured between said plates and supported in such elevated position by the uppermost bolts of each pair embedded in such concrete being tted in the lowermost openings in said plate.

12. A core mold for Wall forms comprising a pair of separable, generally U-shaped plates arranged with their open sides in confronting relation and having the marginal portions along 'their free edges in overlapping relation; means carried by said plates releasably securing the adjacent overlapping marginal portions at each of the opposite sides of said mold together in opposed relation against separaticn thereof under force applied against the outer sides of either of said adjacent marginal portions, said plates being of resilient sheet metal normally free to be forced apart at the said overlapping portions upon application of such force applied against said outer sides of said marginal portions, and means extending between the opposite sides of said mold at the overlapping portions of the plates forming said mold releasably holding said overlapping portions at each of said opposite sides against inward movement toward the center of the mold.

WILLIAM R. BAGOT. 

